Moveable bridge reducers can be quite large and need to be tested to very high torque loads. The bridges also have differential style gearboxes that require load equalizing on each output shaft.

Nuttall technicians utilize the latest testing techniques and technology including laser alignment of all drivetrain components, twin dynamometers, and massive, custom-built test stands which allow two 15,000 lb. gearboxes to be mounted and tested back-to-back on inclines up to 75 degrees.